I recently bought a 2006 F150 STX with the 4.2 V6. I've got 3.55s and an automatic. nice truck. after having it for a couple of months and also driving my mother's '95 Chevy Astro van with the 4.3 V6 i cant help but wonder why Ford couldn't, or didn't, make its 4.2 more like the Chevy 4.3. that Chevy sounds better and works down low in ways the 4.2 wont. i cant even keep up with traffic without turning over 2000 rpm. the numbers back it up. the 4.3 max torque is at 2800 rpm, the 4.2 at 3700. wish ford had made that 4.2 more like the 4.3. any ideas why they didnt? is there some advantage to the 4.2 setup that i'm missing? thanks.

 

What is missing is about 1500 pounds in the Astro van. Torque peak may be lower in the 4.3, but it is flat accross the entire RPM range in the 4.2.

 

i guess what i dont get is that chevy claims a 4.3 with 3.23 rear has a tow rating of 5100 lbs. ford has to go all the way up to a 3.55 rear in the 4.2 to get 5200 lbs. so the 4.3 is pulling almost the same, turning fewer rpms, and burning less gas. isn't all of that better? what advantage does the 4.2 setup provide compared to the 4.3? i'm obviously not an expert on this stuff, just trying to understand whats going on. thanks.

 

You're mainly gonna save gas with the 4.3L due to the engine turning less RPM to stay in it's powerband and won't have to shift as much.

That being said, the tow rating is a lot more based on vehicle than engine.

 

Well, that is what happens when you have a high revving car-based engine, add some cubes to it, then slap it in a truck.

It's out of place.

Conversely, the 4.3L falls on its face around 4500 rpms, so maybe having an engien that can wind itself out is not such a bad thing.

It is basically A to B transportation in a full-size truck, though.

 

I also have a 06 stx with the 4.2 but i got the 5 speed. The manual really helps. It feels more powerful than the 4.3 that I have driven in the past. Mine pulls to 5000 rpm a 4.3 won't.

 

The 4.2 doesnt really open up until you break the 2k rpm range. After that being said, the 4.3 chevy falls on its *** over 3k.

 

The 4.2 also has a dual stage intake with vanes that open up above 2500 rpm (est). This gives it more throttle response at low rpms and opens up to breath at high rpms for more HPs. The biggest problem with the new F150s is they are overweight for the 4.2 and 4.6 V8. Or basically overweight period.

 

yeah, its heavy but i move along nicely. and i saw the new silverado reg. cab is up to about 4450 lb. i'm sitting at 4615lb. what i've noticed with more driving is that i've just about got to floor it for it to break the 2250 rpm mark. it keeps up with traffic without ever breaking 2000 rpm and it takes a pretty steep hill for it to drop a gear when cruising on the interstate--cruising at 75 turns about 2050 rpm. i havent pulled anything yet though so maybe i'll be disappointed when i finally do but i've heard it doesnt drive much differently pulling than it does empty. that 4.6 doesnt make a big enough torque difference to justify the $1K.